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Trial registered on ANZCTR


Registration number
ACTRN12613000180718
Ethics application status
Approved
Date submitted
12/02/2013
Date registered
14/02/2013
Date last updated
14/02/2013
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of olive leaf extract on blood pressure in overweight prehypertensives
Scientific title
The effect of olive leaf extract on blood pressure in overweight prehypertensives
Secondary ID [1] 281934 0
Nil known
Universal Trial Number (UTN)
U1111-1139-4371
Trial acronym
OLE study
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Hypertension 288337 0
Condition category
Condition code
Cardiovascular 288689 288689 0 0
Hypertension

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Subjects will consume 20ml phenolic-rich olive leaf extract liquid (OLE) at home daily for six weeks. There will be a four week wash out period between treatments.
Intervention code [1] 286496 0
Prevention
Intervention code [2] 286512 0
Treatment: Other
Comparator / control treatment
Control will be a polyphenol free placebo liquid, 20ml of which will be consumed daily for 6 weeks.
Control group
Placebo

Outcomes
Primary outcome [1] 288839 0
Blood pressure measured via 24 hour ambulatory blood pressure monitors
Timepoint [1] 288839 0
6 weeks
Secondary outcome [1] 301102 0
Vascular function assessed by pulse wave velocity (PWV)
Timepoint [1] 301102 0
6 weeks
Secondary outcome [2] 301103 0
Lipid profile measured via serum assay
Timepoint [2] 301103 0
6 weeks
Secondary outcome [3] 301104 0
Inflammatory cytokines measured via plasma assay
Timepoint [3] 301104 0
6 weeks
Secondary outcome [4] 301105 0
Fructosamine measured via plasma assay
Timepoint [4] 301105 0
6 weeks
Secondary outcome [5] 301106 0
Glucose measured via plasma assay
Timepoint [5] 301106 0
6 weeks
Secondary outcome [6] 301107 0
Nitric oxide measured via plasma assay
Timepoint [6] 301107 0
6 weeks
Secondary outcome [7] 301108 0
Insulin measured via plasma assay
Timepoint [7] 301108 0
6 weeks
Secondary outcome [8] 301109 0
Haemostatic factors (D-dimer, PAI-1 ag, von Willebrand factor, prothrombin F1+2, factor VIII) measured via plasma assay
Timepoint [8] 301109 0
6 weeks
Secondary outcome [9] 301125 0
oxidised LDL measured via plasma assay
Timepoint [9] 301125 0
6 weeks
Secondary outcome [10] 301126 0
Obesity markers (adiponectin, CCL-2, complement factor D, CRP, IL-6, IL-10, leptin, resistin, serpin E1 and TNF-a) measured via plasma assay
Timepoint [10] 301126 0
6 weeks

Eligibility
Key inclusion criteria
Inclusion criteria:
Men
18-65 years;
Non-smokers;
Prepared to consume olive leaf extract liquid
Systolic blood pressure 121-139 mmHg and diastolic blood pressure 81-89 mmHg
Body mass index (BMI) between 25-30 kg/m2 or waist >102 cm
Minimum age
18 Years
Maximum age
65 Years
Gender
Males
Can healthy volunteers participate?
No
Key exclusion criteria
Exclusion criteria:
Smokers
Using blood pressure, lipid lowering, thyroid disorder, blood clotting medication
Using supplements or functional foods that will affect lipid concentrations (e.g. sterol enriched spreads)
Chronic disease e.g. CHD, diabetes, cancer, digestive disorders
Individuals who are unwilling to refrain from consuming olive containing products for the duration of the study


Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Subjects will be invited for a screening visit after completing a health and lifestyle questionnaire. If they fit the inclusion criteria they will be matched with another subject of a similar blood pressure and BMI and randomly assigned to a treatment. Products will be supplied in opaque bottles labelled with codes. Products will be bottled and labelled offsite so that the researcher and the subjects do not know which product is which.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomization.com will be used to generate random block sizes.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
SPSS will be used

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 4859 0
New Zealand
State/province [1] 4859 0
Auckland

Funding & Sponsors
Funding source category [1] 286720 0
Commercial sector/Industry
Name [1] 286720 0
Comvita
Address [1] 286720 0
Comvita New Zealand Ltd
23 Wilson Road South
Paengaroa
Te Puke 3189
Bay of Plenty
Country [1] 286720 0
New Zealand
Primary sponsor type
University
Name
Massey University, Institute of Food, Nutrition and Human Health
Address
Massey University, Institute of Food, Nutrition and Human Health

Albany Campus, Private Bag 102904, North Shore City, 0745, Auckland

New Zealand
Country
New Zealand
Secondary sponsor category [1] 285493 0
University
Name [1] 285493 0
Department of Food and Nutritional Sciences, University of Reading
Address [1] 285493 0
PO Box 266
Whiteknight's Campus
University of Reading,
RG6 6AP
UK
Country [1] 285493 0
United Kingdom

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 288792 0
University of Reading Research Ethics Committee
Ethics committee address [1] 288792 0
c/o Cat Ashford, Department of Pharmacy, PO Box 266, University of Reading, Whiteknight's Campus, Reading, Berkshire, RG6 6AP UK
Ethics committee country [1] 288792 0
United Kingdom
Date submitted for ethics approval [1] 288792 0
01/12/2012
Approval date [1] 288792 0
Ethics approval number [1] 288792 0

Summary
Brief summary
Cardiovascular disease (CVD) is the leading cause of death in New Zealand (40% of all deaths). 37% of New Zealanders suffer from high blood pressure (World Health Organisation 2008 figures), a well established modifiable risk factor for CVD. Above 115/75 mmHg, CVD risk doubles for each increment of 20/10 mmHg that blood pressure is raised. An increase in BMI and waist circumference has been associated with an increase in blood pressure. The leaves of the olive plant are rich in plant compounds known as polyphenols. This particular group of polyphenols are known secoiridoids, which are also present in olive oil and olives though at lower concentrations, are only found in this family of plants. Diets high in polyphenols have been found to reduce the risk of chronic diseases. Studies have shown that consumption of phenolic-rich olive leaf extract (OLE) can significantly reduce blood pressure in individuals suffering from high blood pressure (hypertension), with the magnitude of effect being comparable to a commonly used antihypertensive drug. In such trials OLE also resulted in an improved blood lipid (a reduction in total and LDL cholesterol and triacylglycerides) which also reduces CVD risk. One study testing the effect of OLE on individuals with mild or prehypertension (i.e. those with systolic blood pressure in the range 121–139 mmHg and diastolic blood pressure in the range 81-89 mmHg but not taking antihypertensive medication) also found these same improvements. OLE has been indicated to have the potential to improve other cardiovascular risk markers such as vascular function, inflammation, platelet aggregation, oxidation of LDL and glucose tolerance however much of this evidence is derived from animal, in vitro and ex vivo studies and so well designed and controlled human studies are required to verify that these findings are applicable to humans. Therefore OLE supplementation may be a useful dietary strategy for reducing CVD risk in a cohort of overweight prehypertensive individuals.
The aim of the study is to determine the effect of OLE intake on blood pressure and other CVD risk markers in overweight subjects with mild hypertension and to link any study outcomes with the presence of OLE phenolics in urine
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 37766 0
A/Prof Welma Stonehouse
Address 37766 0
Massey University, Institute of Food, Nutrition and Human Health

Albany Campus, Private Bag 102904, North Shore City, 0745, Auckland

New Zealand
Country 37766 0
New Zealand
Phone 37766 0
+64 9 443 9755
Fax 37766 0
Email 37766 0
w.stonehouse@massey.ac.nz
Contact person for public queries
Name 37767 0
Miss Stacey Lockyer
Address 37767 0
Massey University, Institute of Food, Nutrition and Human Health

Albany Campus, Private Bag 102904, North Shore City, 0745, Auckland

New Zealand
Country 37767 0
New Zealand
Phone 37767 0
+64221762729
Fax 37767 0
Email 37767 0
s.lockyer@pgr.reading.ac.uk
Contact person for scientific queries
Name 37768 0
Miss Stacey Lockyer
Address 37768 0
Massey University, Institute of Food, Nutrition and Human Health

Albany Campus, Private Bag 102904, North Shore City, 0745, Auckland

New Zealand
Country 37768 0
New Zealand
Phone 37768 0
+64221762729
Fax 37768 0
Email 37768 0
s.lockyer@pgr.reading.ac.uk

No information has been provided regarding IPD availability
Summary results
No Results